Dry cleaning composition and method of use



Filed July 2'7, 1959 May 28, 1963 5 WWW M m m M Z M My. g My NW 5 Q United States Patent 3,091,508 DRY CLEANING cognggl rloN AND METHOD Le Roy B. Edwards, 9022 Karlov Ave., Skokie, 111. Filed July 27, 1959, Ser. o, 829,584 8 Claims. c1. 8-142) This invention relates to a new dry cleaning process and compositions for use in same and more particularly to a new and improved dry cleaning composition wherein a more complete removal is achieved of spots and dirts and wherein such removal is achieved in a simpler and more efficient manner.

It is an object of this invention to produce a composition for use in dry cleaning wherein such dry cleaning operations can be effected in an eflicient and economical manner to provide for a more complete removal of dirt and of spots and it is a related object to provide a new and improved cleaning composition and method for use of same.

These and other objects and advantages of this invention will hereinafter appear and, for purposes of illustration, but not of limitation, an embodiment of the invention is shown in the attached drawing, in which the sole FIGURE in the drawing is a schematic diagram of the dry cleaning operation.

In conventional dry cleaning for the removal of dirt and spots from fabrics and garments formed thereof, use is made of a liquid dry cleaning composition which is formulated of a solvent used alone but preferably in combination with a detergent for modification of the surface tension and to facilitate the action of the solvent in dissolving or otherwise removing the dirt. In present dry cleaning, the composition is often also formulated to contain an amount of moisture for the removal of water spots and to. dissolve. stains and dirt which are water soluble and relatively solvent insoluble.

As the solvent'base for. the. dry cleaning composition, use. is usually made of a hydrocarbon or a chlorinated hydrocarbon which is volatizable at ambient temperature for. elimination of the last traces of solvents in the dry cleaning and pressing. operation which usually follows cleaning. As the volatizable hydrocarbon solvent, use can. be made of benzene, gasoline, naphtha, Stoddard solvents and the like. As the chlorinated solvent, use can be made. of carbon tetrachloride, perchlorethylene, trichlorethylene and the like. These operate to dissolve the oily. films anchoring the dirt to remove the oil and free the dirt for separation as the fabric or garment is tumbled through the liquid bath of the cleaning composition.

The term -detergentf is meant to include dry cleaning soapsand synthetic detergents such as the alkali metal soaps offatty' acids or fatty acid esters as represented by. sodium or potassium palmitate, sodium or potassium stearate, sodium or potassium oleate or sodium or potassium laurate. Representative of the synthetic surface active agents are the alloyl aryl sulfonates or sulfates and esters thereof such as are described in United States Patents No. 2,388,962, No. 2,327,183, No." 2,327,182, No. 2,326,772, No. 2,271,635, No,2,2 l90,8170 and No. 2,181,087; the sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan sequioleate, and sorbitan trioleate; glycerol fatty acid esters such as glyc eryl monostearatej and polyo ryethylene derivatives of sorbitan fatty acid esters or other fatty acid esters, and others such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan tristearate, polyoxyethylene sorbitan monooleate, polyoxyethyle 2 ene sorbitan trioleate, polyoxyethylene stearate, polyoxy-v ethylene oxypropylene monostearate, polyoxyethylene lauryl ether, polyoxyethylene oleyl ether and the like. Ifhese materials may be employed alone or in admixture with each other in the solvent system. When soaps are employed, the concentration in the cleaning composition may range from .5-10 parts by weight per parts by weight of the solvent when used as a dry cleaning composition and up to equal parts by weight when used as a spotting agent, depending upon the type of soap, the solvent and the fabric being cleaned. In the use of a synthetic detergent, a much lower concentration is usually employed ranging from .10-5.0 parts by weight and preferably from .25-3 parts by weight of the solvent component when used in dry cleaning and up to 20 parts by weight when used as a spotting agent. More detergent can be employed but the advantage in the use of higher concentrations is not offset by the increased cost.

For the removal of marks or configurations called water spots which are caused by water having come into contact with the fabric to cause roughening of the fibers or partial solution of; the finishing materials or for the removal of spots caused chiefly by water soluble sub- SIJQI WS 5 10b as perspiration, soft drinks, sugar syrup and the like, it is desirable to make use of a cleaning composition having a controlled amount of water or moisture for the removal of such spots but without such excessive amounts of moisture as would deleteriously \affect the fabric, dyestuif or the finish of the fabric. Detergents of the type employed in the practice of this invention are effective to bring a certain amount of water into the liquid cleaning composition without causing the separation thereof from the solvent system. Thus the detergent can be employed as a means for controlling the amount of water depending somewhat upon the type and amount of detergent or solvent employed in combination therewith. When water is employed in the cleaning composition, it is. usually desirable to calculate for an amount,

of water ranging from .1 percent up to about 5.0 percent by volume of the cleaning composition or preferably about .5-5 parts; by weight of water per 100 parts by weight of the cleaning composition. The desired concentration is maintained best by control of the relative humidity in the dry cleaning plant to 60-80 percent relative humidity.

In accordance with the practice of this invention, the characteristics of the dry cleaning composition are materially enhanced when the dry cleaning composition is,

formulated to contain in combination with the solvent and detergent, a, polyhydric alcohol and preferably a polymer thereof. As the polyhydric alcohol or the ester thereof or the. polymer thereof, hereinafter referred to, as the polyhydri c alcohol polymer component, use can be made of ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol and mixturesv thereof. When, as in the preferred practice, use is made of a polyhydric alcohol polymer, it is,preferr ed to make use of a polymer of low molecular weight such as less than. 10,000. average molecular weight and more preferably from 200 to about 60 0 average molecular weight. The lower molecular weight polyhydric alcohol polymers are liquids which are eely and, completely soluble in the system of the dry, cleaning composition, while the higher molecular weight Compounds are less soluble but nevertheless miscible withthecomponents of the dry cleaning composition, especially in the small. amounts, in which these materials are emp oy d.

The polyhydric alcoholpolymer islemployed; in the deseribed; dry cleaning composition in an amount greater than,.2 part by weight per 100 parts by weight-,of cleaning fluid, anduptoabout ldparts by weight per 100 parts by weight of cleaning fluid. While an amount greater than parts by weight per 100 parts by weight of cleaning fluid can be employed, no material improvement is secured to justify the additional cost. It is preferred to make use of a dry cleaning composition formulated to contain from l-3 parts by weight of the polyhydric alcohol polymer per 100 parts by weight of the dry cleaning composition.

The mechanism whereby the polyhydric alcohol polymer is effective to enhance the cleaning act-ion of the composition is not yet known. It is believed however that the polyhydric alcohol polymer functions in lieu of water to remove water spots and to dissolve or soften the water soluble material in the fabric to enhance their removal thereby to minimize the need for water in the cleaning composition or the amounts thereof in the cleaning composition. At the same time the polyhy-dric alcohol polymer or ester is believed to enhance the reaction of the solvent and detergent in loosening the dirt for removal whereby a more effective and more efiicient cleaning operation is achieved in shorter time Without adding to the wrinkling of the fabric. As a result, it is possible, in accordance with the practice of this invention, to make use of some garments after removal from the tumbler Without the necessity of an intervening pressing operation.

The polyhydric alcohol polymer is hydroscopic in character such that it is effective in maintaining a. desired moisture balance in the garment and in the cleaning composition whereby the water concentration is automatically adjusted such that it becomes unnecessary frequently to adjust the moisture content to insure the elimination of water spots and Water soluble dirt without the danger of incorporating excesses in the amount of moisture as would otherwise deleteriously affect the fabrics and fibers formed thereof.

In addition to the ability of the polyhydric alcohol polyrner or ester to replace water and control water balance, the compound, in combination with a solvent and detergent, operates to maintain and improve the hand, body and feel of the fabric whereby a fabric or garment cleaned with a composition embodying the practice of this invention is characterized by an improved appearance and cleaner look. Some of the polymer is believed to remain in the fabric in small amounts where it can function as a textile lubricant to replace natural lubricants which were otherwise extracted during the cleaning operation whereby the fabric acquires the life and feel of a new garment.

More important even is the unexpected improvement which is secured in the action of the cleaning composition whereby the number of garments capable of being cleaned per unit volume of cleaning composition used is markedly increased. Such improvement in yield is incapable of being explained by any characteristics of the polyhydric alcohol polymer. It is believed that the latter operates synergistically to assist the solvent and detergent in the cleaning operation with a marked reduction in the loss by evaporation or deterioration thereof whereby less composition is consumed per unit fabric cleaned. The improveanent in yield can be measured in multiples of from 200 to 500 percent by comparison with the yield of a cleaning composition formulated of the same component with the exception of the presence of a polyhydric alcohol polymer. The improvement can be measured in an even higher multiple when the dry cleaning process embodies the improvements defined in my copending application Ser. No. 829,583, filed concurrently herewith and entitled Drycleaning Process and Composition. In the copending application, description is made of a process wherein the detergent, in the form of a liquid concentrate, is introduced to the cleaning composition substantially continuously during the cleaning operation to maintain the concentration of detergent at an optimum level for the use of the fluid in a cleaning operation. In accordance with the practice of this invention, the improvements provided by the aforementioned copending application and the im provements of the present application can be achieved all together when the polyhydric alcohol polymer and detergent are combined as a concentrate added to the liquid dry cleaning composition during the cleaning operation to maintain the level of detergent and the level of the polybydric alcohol polymer for maximum efiiciency and use.

The following will represent a cleaning composition embodying the features of this invention:

Example I parts by weight naphtha .15 parts by weight detergent 1-3 parts by weight polypropylene glycol polymer Example 11 100 parts by weight perchlorethylene 5 parts by weight ethyldiphenyl phosphonate 1 part by Weight polyethylene glycol .5 part by weight water Example 111 100 par-ts by weight perchlorethylene 1 part by weight detergent (sorbitan sesquioleate, polyoxyethy-lene sonbitan trioleate-equal parts) 1 part by weight polyethylene glycol polymer (200 M.W.)

Example IV 100 parts by weight Stoddard solvent 2.0 parts by weight detergent 4 parts sonbitan monooleate 1 part polyoxyethylene sorbitan monolau-rate 1 part sorbitan sesquioleate .66 part by weight polyethylene glycol polymer 500 average molecular weight Example V 100 parts by Weight perchlorethylene 3 parts by weight detergent 5 parts sorbitan monooleate 1 part polyoxyethylene sorbitan monooleate 1 part sorbitan tiioleate 1.0 part by weight polyethylene glycol 200 average molecular weight Having described the concepts of the invention and the unexpected advantages and improvements which are secured, illustrations will now be made of the use of the composition in a dry cleaning system embodying the concepts of the aforementioned copending application. It will be understood that the composition embodying the features of this invention may be employed as a dry cleaning composition in conventional dry cleaning systems of the type presently being employed.

Referring now to the drawing, the numeral 10 indicates a dry cleaning washer of the type well known to the art which is provided with the usual wheel 12 rotatably mounted therein for flushing the cleaning solvent 14 through the garments 16.

. Means are provided for circulating the liquid cleaning composition through the washer including, in series, a lint and button trap 18 connected by line 24 with the bottom of the washer; a pump 22 in line 24 leading from the trap 18 to the filter 26 for forcing the cleaning liquid to and through the filter in which soil is removed from the liquid cleaning composition. A sight glass 28 is provided in the return line 30 connecting the filter with the washer for permitting visual inspection of the liquid cleaning composition entering the washer and another sight glass 32 is provided in line 24 to permit visual inspection of the liquid cleaning composition leaving the washer whereby a comparison can be made between the liquid entering and leaving the washer to determine when the dirt has been substantially completely removed from the garments. Make up solvent is introduced into the system as required from a supply source to replace the solvent removed from the system with the garments or by vaporization.

The concentrate of detergent and polyhydric alcohol polymer for continuous addition to maintain the desired spam level in the dry cleaning composition is provided in a reservoir tank 36; The liquidconcentrate is displaced from the reservoir tank in'to' line 38 by displacement pump 40 for the introduction of the concentrate into the liquid drycleaning composition for admixture therewith. In the illustrated modification, theli'n'e 3&cornmunicates with the line 30 beyond the filter l but before the 'was'henlll. Instead, the line 3'8may be 'conn ectedto introduce the concentrate directly into the washer or it maybe connected to the line 24 beyond the washer, or to the filter 26 or to-a reservoir for thedry cleaning composition for the constant replenishmenfof the 'detergent and polyhydric' alcohol polymer or ester to tain the materials atth'e desired level.' lnthe preferred practice, the displacement means is 'connected'foropera tion durin'gthe cleaning cycle 'toreplace detergent and polyhyd'ric alcohol polymer which are removed in the garment or filter during the cleaning operation Instead of circulating the liquidcleaningcomposition fromthe' filters directly to the Washer the composition may be returnedto a supply source from" which'it is fedto the washer.' 4

The amount of concentrate introduced into the system may be var e by adjustmentor the stroke ofth'e dis placement "means or" byunereasing or decreasing the rate of operation thereof, as the case may be, depending on the type of'displacement means which is employed.

The following is an illustration of concentrate which may be used, in accordance with this modification, for maintaining the desired level of detergent and polyhydric alcohol polymer in the liquid composition. -It will be understood that the concentrate composition may be varied depending upon the original compositiono'f the liquid dry cleaning composition, 'the materials being cleaned and the method of use thereof.

Example VI Concentrate for use with composition of Example IV:

4 parts by weight sorbitan monooleate 1 part by weight polyoxyethylene sorbitan monolaurate 1 part by weight sorbitan sesquioleate 2 parts by weight polyethylene glycol (M.W. 500) Example VII Concentrate for Example III:

2 parts by weight sorbitan sesquioleate 2 parts by weight polyoxyethylene sorbitan trioleate 4 parts by weight polyethylene glycol (200* M.W.)

When constant addition is made of the concentrate to maintain the level of detergent and polyhydric alcohol polymer in the dry cleaning composition, the concentrate is charged into the system at a rate calculated on the basis of about /2 to 1 ounce of concentrate per 100 pounds of garments processed through the system. This is to be compared with the use of as much as ounces of detergent per 100 pounds of garments processed with cleaning compositions of the types heretofore employed.

The following will enumerate some of the improvements which have been experienced by the practice of this invention. Many of the improvements secured are incapable of explanation. Others flow from the synergistic combination of materials employed.

(1) When dry cleaning compositions embodying the practice of this invention are employed, it becomes possible to run mixed loads, that is light and dark materials, with a minimum of lint. Thus the system embodying the features of this invention makes it possible to eliminate the separation steps and multiple loads heretofore employed and without noticeable increase in color bleeding.

(2) The duration of the cleaning cycle has been markedly reduced from about 30 minutes to about .15 minutes for washing in Stoddard solvent or from *8 minutes to 4 minutes when the washing is carried out in a perchlorthis invention. In the light of the high cost "of perchlorethylene, detergent and polyhydric alcohol polymer, this increase'in yield represents an important savings in the dry cleaning cost per garment.

(4) It has been hound further that the drying time is reduced 'by as much as 25 percent when use is made of a dry cleaning composition embodying the concepts of this invention. v

(5) -It has been found further that a clear dry cleaning composition free of nancidity can be maintained Without the necessity to distill the composition [for the removal offiatty acids. Thus the soaps or detergents removed by distillation are saved thereby to provide considerable savings in raw material costs while also eliminating a step andequipment generally employedin the dry cleaning operation. A

(6) I t becomes unecessary to rinse the garments after the wash since the materials remaining inthe garment appear b n fic y t9 effect t i e n appe rance of the cleaned garment.

(7)'It has been found that many operators who were allergie 'to the solvent systems heretoiore employed in y cleaning pr s Wa e ate the qu pment a d even handle the clothes wet with the cleaning composition embodying the practice of this invention without breaking out and without the necessity of taking special precautions or protections to prevent rash or irritation by the solvent system.

(8) The garments dry cleaned with compositions cmbodying the practice of this invention appear to come out cleaner and brighter by comparison with the appearance and color of the same garments processed in dry cleaning comopsitions of the type heretofore employed.

It will be apparent from the foregoing that I have provided a new and improved composition and method for use in dry cleaning to improve efiiciency of the dry cleaning processes and greatly to extend the life of the materials employed therein.

It will be understood that changes may be made in the details of the formulation of materials in the dry cleaning composition and in the dry cleaning process without departing from the spirit of the invention, especially as defined in the fiollovving claims.

I claim:

1. A dry cleaning composition consisting essentially of an organic solvent as a base, 0.2540 parts by weight of detergent per parts by weight of solvent, 0.2-10 parts by Weight of a compound selected from the group consisting of a polyhydric alcohol and polymer thereof of less than 10,000 molecular weight per 100 parts by weight of solvent, and 0.1-5 parts by weight of water per 100' parts by Weight of the dry cleaning composition.

2. A dry cleaning composition consisting essentially of an organic solvent as a base, 0.25-3 percent by weight of detergent per 100' parts by weight of solvent, 0.2-10 parts by Weight of a compound selected from the group consisting of a polyhydric alcohol and polymer thereof of less than 10,000 molecular weight per 100 parts by weight of solvent, and 1-5 parts by weight of water per 100 parts by Weight of the dry cleaning composition.

3. A dry cleaning composition consisting essentially of an organic solvent as a base, 0.25-3 pants by Weight of detergent per 100 parts by weight of solvent, 1-3 parts by weight of a compound selected from the group consisting of a polyhydric alcohol and polymer thereof of less than 10,000 molecular weight per 100 parts by weight of solvent, and 0.1- parts by weight of water per 100 parts by Weight of the dry cleaning composition.

4. A dry cleaning composition as claimed in claim 3 in which the solvent is perchloret-hylene.

5. A dry cleaning composition as claimed in claim 3 in which the solvent is Stoddard solvent.

6. A dry cleaning composition as claimed in claim 3 in which the polyhydric alcohol polymer is polyethylene glycol having a molecular weight less than 1000.

7. In a method of dry cleaning textile materials in an organic dry cleaning solvent system which includes the steps of washing the textile material in a dry cleaning solvent system by circulating the solvent system through a washer containing the textile material, filtering the dry cleaning solvent after passage through the washer, and returning the filtered dry cleaning solvent system to the washer, wherein the dry cleaning solvent system consists essentially of an organic solvent as a base, 0.25- parts by weight 04: detergent per 100 parts by weight of solvent, 0.2-10 pants by weight of a polyhydric alcohol polymer per 100 parts by weight of solvent, and 0.5 parts by weight of water per 100 parts by weight of the dry cleaning composition, the improvement of continuously introducing a concentrate of the detergent and polyhydric alcohol polymer in the proportions present in the dry cleaning composition to the dry cleaning solvent system during the dry cleaning operation in an amount to correspond to about the amount removed from the dry cleaning solvent system during the dry cleaning operation thereby continuously to maintain the level of the detergent in the dry cleaning solvent system at about the level originally present in the dry cleaning system.

8. In the method of dry cleaning textile materials in an organic dry cleaning solvent system including the steps of introducing the textile material into a washer, circulating the dry cleaning solvent system through the washer and the textile material therein, filtering the dry cleaning solvent system removed from the washer, returning the filtered dry cleaning solvent system to the washer with sufficient make-up solvent to maintain substantially the original volume, and removing the textile material from the Washer after cleaning, wherein the dry cleaning solvent system. consists essentially of an organic solvent as a base, 0.5-3 parts by weight of detergent per parts by weight of solvent, 1-3 parts by weight of a polyhydric alcohol polymer per 100 parts by weight of solvent, and 0.1-5 parts by weight of water per 100 parts by weight of dry cleaning composition, the improvement of continuously adding a concentrate of the detergent and polyhydric alcohol polymer in the proportions present in the dry cleaning composition to the dry cleaning solvent system during the dry cleaning operation in an amount to correspond to about the amount removed from the dry cleaning solvent system during the dry cleaning operation thereby continuously to maintain a level of the detergent in the dry cleaning solvent system at about the level originally present in the dry cleaning system.

References Cited in the file of this patent UNITED STATES PATENTS 1,385,724 Smith et al July 26, 1921 2,059,475 Myers Nov. 3, 1936 2,614,026 Lascari Oct. 14, 1952 2,669,546 Zussman et al Feb. 16, 1954 2,717,824 Avery Sept. 13, 1955 2,729,576 Trusler Jan. 3, 1956 

7. IN A METHOD OF DRY CLEANING TEXTILE MATERIALS IN AN ORGANIC DRY CLEANING SOLVENT SYSTEM WHICH INCLUDES THE STEPS OF WASHING THE TEXTILE MATERIAL IN A DRY CLEANING SOLVENT SYSTEM BY CIRCULATING THE SOLVENT SYSTEM THROUGH A WASHER CONTAINING THE TEXTILE MATERIAL, FILTERING THE DRY CLEANING SOLVENT AFTER PASSAGE THROUGH THE WASHER, AND RETURNING THE FILTERED DRY CLEANING SOLVENT SYSTEM TO THE WASHER, WHEREIN THE DRY CLEANING SLOVENT SYSTEM CONSISTS ESSENTIALLY OF AN ORGANIC SOLVENT AS A BASSE, 0.25-10 PARTS BY WEIGHT OF DETERGENT PER 100 PARTS BY WEIGHT OF SOLVENT, 0.2-10 PARTS BY WEIGHT OF A POLYHYDRIC ALCOHOL POLYMER PER 100 PARTS BY WEIGHT OF SOLVENT, AND 0.5 PARTS BY WEIGHT OF WATER PER 100 PARTS BY WEIGHT OF THE DRY CLEANING COMPOSITION, THE IMPROVEMENT OF CONTINUOUSLY 